The present invention relates to container-closure assemblies and more specifically to a novel combination which is extremely economical to manufacture and is effective for the purposes intended.
The present invention relates particularly to a container-closure combination adapted for packaging pharmaceuticals or the like. Some of these containers are provided with a so-called blind end or membrane and the closure has a piercing element which can be actuated to puncture the membrane to permit discharge of the packaged product. In this way a pharmaceutical product may be packaged in a sterile, enclosed environment and the closure actuated on demand by a doctor or hospital personnel to release the product when needed. The closure is usually provided with some visual indicating means to indicate to the user that the membrane has been punctured and thereby the container-closure assembly is characterized as being tamper-proof.
Container-closures of this type are not new per se. For example the Henderson U.S. Pat. No. 2,771,218 shows a closure-assembly for pharmaceutical, medicinal and biological preparations packaged in a container with a blind end or a membrane. In this instance the closure-cap which is threadedly received on the container has a central conical piercing tip which in the unarmed position of the assembly is spaced from the membrane and is maintained in that position by means of lugs projecting from the sidewall or finish of the container in one embodiment so that when it is desired to arm the container and puncture the membrane, the cap is simply threaded downwardly to fracture the radially projecting ribs on the container and permit the closure or cap to be actuated to a position wherein the membrane is punctured by the piercing element.
In another form of the invention, the cap is provided with a series of axially projecting frangible legs which engage the body of the container below the neck in the unarmed position. Now when the cap is rotated, the leg members are fractured to permit the piercing element to puncture the membrane. While this assembly is generally effective for the purposes intended, it is, nevertheless, possible with this type of container-closure assembly to remove the closure and reapply it after puncturing the membrane and there is, therefore, no visual indicia that the assembly has been tampered with.
Another so-called collapsible tube-type container with a membrane is shown in the Ferris U.S. Pat. No. 3,109,562. This assembly simply has a collar which is removably mounted on the outer end of the cap which must be removed to permit arming of the assembly. This provides some visual indicia. However, it presupposes that the user is aware that the cap includes the removable tear band portion.